How Presidents Used Local Police to Expand Immigration Enforcement — and the Hidden Costs

Big Question: Why Invite Local Police into Immigration Enforcement?

This paper asks why the federal executive invited local law enforcement into interior immigration policing and what consequences followed. Over the past few decades, U.S. local police have cooperated with federal immigration authorities at unprecedented levels. The paper frames that cooperation not as accidental but as an intentional use of presidential authority to extend enforcement capacity.

Theory: An Agency Perspective on Delegation

Building on bureaucratic agency literature, the paper develops a formal model of a president's decision to invite subnational participation in policymaking and enforcement. The model highlights a central trade-off: deputizing local officers shares enforcement costs with subnational partners (a fiscal and capacity gain) but risks empowering local actors whose preferences differ sharply from the federal government (a political cost labeled here as "extremism").

Evidence: Empirical Analysis of the 287(g) Program

The paper tests the model using empirical analysis of the 287(g) program, which deputizes local officers to act as federal Immigration and Customs Enforcement agents. The empirical work shows:

• 287(g) induced a substantial increase in immigration policing while imposing relatively little federal fiscal burden;
• jurisdictions that enrolled were often preference outliers compared to federal enforcement priorities;
• those local actors used their new authority to escalate enforcement, especially by policing low-level offenses such as misdemeanors and traffic violations.

What This Means: Trade-Offs in Immigration Federalism

The findings suggest presidential delegation can rapidly expand enforcement capacity at low federal cost, but the strategy invites uneven and sometimes more aggressive local practices that diverge from federal norms. The paper highlights implications for debates about federalism, bureaucratic control, and the political consequences of outsourcing enforcement to subnational actors.

Methods Summary:

• Formal model grounded in bureaucratic agency theory to derive testable predictions about costs and political risks of delegation.
• Empirical evaluation of the 287(g) program to assess selection into the program and changes in enforcement behavior following deputization.

Overall, the paper contributes to understanding how executive strategies of delegation reshape enforcement on the ground and the political trade-offs inherent in immigration federalism.